Housings for portable electronic devices are often fabricated from injection molded plastic to minimize production costs and weight. For example, in a typical plastic clam shell housing for such a device, the two halves of the plastic housing are connected together with fasteners; internal components are typically connected to one half of the housing using fasteners. However, in addition to being relatively lightweight, portable medical devices, such as ambulatory infusion pumps, must also be relatively rugged and resistant to mechanical shock and breakage if accidentally mishandled or dropped. Failure of a portable medical device due to undetected damage sustained in a short drop or as a result of other mechanical shock could be life threatening to a patient. Because infusions pumps of this type are often carried about by a patient for extended periods of time, they are likely to be frequently bumped and occasionally dropped. Lightweight plastic cases or conventional metal housings are generally unable to withstand such rough handling without damage to either the housing or the internal components of an ambulatory infusion pump. A further drawback to using plastic housings for such devices is that it is often necessary to include a metal plate or foil layer within the plastic material to shield against electromagnetic or radio frequency noise. The additional metal shielding adds weight and cost.
Also, because an ambulatory infusion pump may have to be coupled to a patient's vascular system at all times, even when the patient is bathing or showering, the infusion pump must be sufficiently watertight to be briefly immersed in water or exposed to water droplets in a shower. Providing a sealed, watertight housing for an infusion pump that has patient actuated controls and a display panel, and which accepts disposable pumping cassettes is not a trivial task, particularly when the housing must also be lightweight, rugged, and relatively low in cost, as noted above. Previous attempts to provide such a housing fabricated using injection molded plastic or metal have generally not been successful. It is somewhat difficult to provide sealed closure of a battery compartment and of the components that interact with a disposable cassette in a housing that is also lightweight, low cost, and capable of withstanding physical shock. Accordingly, it will be apparent that there is a need for such a housing that is not met by the available prior art.